KR20150098942A - Back light optical system - Google Patents

Abstract

The present invention relates to a backlight optical (lighting) system which makes thickness thinner by reducing an optical distance and reduces costs by using a technology of removing an optical sheet completely at the same time. The present invention includes a lens for changing a light path formed in a front side of traveling direction of a light in a light emitting device (generally LED) radiating light; and a reflective sheet for reflecting light which is radiated from the light emitting device and is reflected (or scattered) by a lens or the like. The lens comprises a first refraction medium (face) for traveling light to the inside of the lens by refracting light emitted from the light emitting device and a second refraction medium (or face) for refracting light traveling inside the lens by refraction to the outside of the lens wherein the outside of the lens in the second refraction medium comprises at least one face, wherein at least one face on a surface of the lens can play a role as a support rod in order to place other flat plate or image display element on the lens. The first or the second refraction medium of the lens forms at least one or more refraction angles for scattered light of the light emitting device spreading evenly in an emitting surface. In addition, the lens, as another medium of making light dispersion evenly, includes a light dispersion figure or a certain material inserted into the surface of the lens or material comprising the lens partially. The present invention is characterized by using the optical system as a backlight of an image display element (especially, LCD) by combining with a polarization sheet or an optical sheet in LCD bottom. Moreover, the present invention forms a flat plate on a lens surface, and the flat plate is used as a lighting system of an advertisement sign.

Description

BACK LIGHT OPTICAL SYSTEM

The present invention relates to a backlight optical (illumination) system.

Light emitting devices (generally LEDs) emitting light; A lens provided in front of the light traveling direction of the light emitting device to change a path of light; (Or a light) system comprising a reflector for reflecting light emitted from a light emitting element by reflection or scattering by a lens or the like and re-reflecting the returned light.

The present invention relates to a backlight optical (illumination) system.

Light emitting devices (generally LEDs) emitting light; BACKGROUND OF THE INVENTION [0002] A backlight optical system for uniformly distributing light of a light emitting device is roughly classified into two types.

A light guide provided in a light traveling direction of an LED array; Optical sheets installed on a light guide plate; There is a side optical input system composed of image display elements provided on a light emitting surface of an optical sheet and another is a direct optical input type backlight optical system in which a function of the light guide plate is replaced by a lens. .

The side-type backlight in which the light guide plate is used has the advantage of being thin, but the price of the light guide plate may be higher than the direct type. The direct type backlight system can be light in weight because the light guide plate is not used, and LED scanning and local dimming are advantageous compared with the side system, so that it is advantageous to realize a high image quality. However, a direct-type backlight requires an optical length that uniformly spreads the light emitted from the LEDs in the lens, which generally causes the backlight thickness to become thick.

Light emitting devices (generally LEDs) emitting light; A lens provided in front of the light traveling direction of the light emitting device to change a path of light; An optical sheet provided in front of the light emission of the lens; In an optical system constituted by an image display element provided in front of a light propagation direction of an optical sheet, a light thickness between the optical sheets in the light emitting device is long and a thick thickness is reduced.

Also, in the conventional technique, it is desired to reduce the cost by using a technique of completely removing the optical sheet.

In order to solve this problem, in order to solve such a problem, at least one planar or plane equivalent area is secured on the lens light exit surface side (second refracting surface) to seat the bottom plate with the light incidence side polarizing plate of the optical sheet or image display device / RTI >

The lens of the present invention includes a first refracting means (surface) for refracting the light emitted from the light emitting element and advancing the light toward the inside of the lens, a second refracting means (or a surface for refracting the light refracted inside the lens toward the outside of the lens, And an optical system.

The lens first refracting means or the second refracting means is characterized in that at least one refraction angle is formed so that the emitted light of the light emitting element emits light evenly on the exit surface of the lens.

Also, the first or second refracting surface includes a spherical surface or an aspherical surface or an oblique surface having a plurality of curvatures so that at least one refracting angle is formed.

Further, as another means for making the light distribution uniform, the lens includes a light diffusion shape or a specific material inserted into the lens surface or a material constituting the lens.

The present invention can reduce the cost and weight by eliminating the optical sheet, and can also reduce the thickness by reducing the light distance.

In addition, high-quality images can be realized simultaneously with scanning and local dimming, which are advantages of direct backlighting.

1 is a block diagram of an optical system according to the present invention.
FIG. 2 is a view showing a configuration in which a lens incident side and an emission side are a plurality of refracting surface shapes according to an embodiment of the present invention.
3, 4 and 5 are specific embodiments of the second embodiment as an embodiment of the present invention.
Fig. 6 shows an example of application of a small disperser on the lens surface as an embodiment of the present invention
Fig. 7 shows an example of application of a small disperser in a lens as an embodiment of the present invention
8 is a view showing the spread of light by a small disperser on the surface of a lens as an embodiment of the present invention.
FIGS. 9, 10 and 11 show another embodiment of the present invention, in which the lens incident side and the exit side form a plurality of refracting surface shapes.
12 is a diagram showing another embodiment of the present invention in which a lens incidence side and an emission side have a plurality of refracting surface shapes.
13 and 14 show another embodiment of Fig. 12 as an embodiment of the present invention
[Description of reference numerals]
10 light source (LED)
20 circuit connection board (PCB) connected to light source (LED)
30 lens
40 A flat plate (or reflector) installed so that the light source and the lens are placed,
50 optical sheet (or LCD lower plate polarizer)
301 to 304, 310 Lens outer surface Segment
305 to 309 Lens Inside Segment
500 Diffuser on the lens surface side
601 to 602 Lens outer surface
603 to 604 Lens side

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: FIG.

The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

The present invention relates to a backlight optical (illumination) system.

1, FIG. 2, FIG. 12, and FIG. 15

An LED 10 as a light emitting element that emits light; A substrate (20) connected to a drive system for applying current to the LED; A lens 30 provided in front of the light traveling direction of the light emitting device to change a light path; A flat plate (40) for supporting the lens and the LED; And an optical sheet (50) provided in front of the light emitting side of the lens or a TFT LCD (50) as an image display element.

The planar plate 40 may include a sheet that reflects light inside the planar plate.

The light emitting element can generally be interpreted as an LED, and the LED includes a plurality of light emitting elements that emit white light or emit white light. For example, a combination of Red, Green and Blue, or may be composed of Yellow, Magenta, and Cyan.

Further, an LCD display device may be provided in front of the light exit side of the optical sheet 50. [

The optical system includes a plurality of light emitting devices or lenses, and an array is formed on the reflector at a predetermined distance. Here, it is preferable that the plurality of light emitting elements are formed in the same number as the plurality of lenses.

It is also preferable that the central axes of the lens and the light emitting element are arranged so as to be coincident with each other.

2 and FIG. 12,

The lens includes a first refracting means (surface) for refracting the light emitted from the light emitting element to advance the light toward the inside of the lens, and a second refracting means (or surface) for refracting the light traveling from the inside of the lens to the outside of the lens. And the lens outside of the second refraction means is provided with at least one plane. Wherein at least one plane of the lens surface can serve as a support for placing another flat panel or image display element on the lens.

The lens first refracting means or the second refracting means is characterized in that at least one refraction angle is formed so that the emitted light of the light emitting element emits light evenly on the exit surface of the lens.

The lens includes a first refracting means (surface) for refracting the light emitted from the light emitting element to advance the light toward the inside of the lens, and a second refracting means (or surface) for refracting the light traveling from the inside of the lens to the outside of the lens. And the lens outside of the second refraction means is provided with at least one plane. Wherein at least one plane of the lens surface can serve as a support for placing another flat panel or image display element on the lens.

In Fig. 2, an example in which the inner surface of the lens (first refraction means) is composed of an oblique surface having five refraction properties and the outer surface of the lens (second refraction means) is composed of an oblique surface having four refraction properties .

The lens having the feature of FIG. 2 shows a specific embodiment of each of the oblique faces in FIGS. 3, 4 and 5.

In FIG. 3, the light emitted from the ends A and B of the light emitting portion of the LED functions as an element for determining the characteristics of the inner light incident portion 307 and the outer light incident portion 302 of the lens. As an example, it is preferable that the boundary between the lens inner incident portion 306 and the adjacent inner incident portion 307 be based on the portion where Ray 2 and Ray 3 meet.

In FIG. 4, the light emitted from the ends A and B of the light emitting portion of the LED functions as an element for determining the characteristics of the inner light incident portion 308 and the outer light incident portion 303 of the lens. As an example, it is desirable that the boundary between the lens inner incident portion 308 and the adjacent inner incident portion 307 should take into account the amount of reflection of the s-wave that is emitted from the lens and reflected by the lens sheet 50 of the first degree .

In FIG. 5, the light emitted from the ends A and B of the light emitting portion of the LED functions as an element for determining characteristics of the inner light incident portion 307 and the outer light incident portion 302 of the lens. As an example, it is preferable that the boundary between the lens inner incident portion 308 and the adjacent inner incident portion 307 be based on a portion where Ray 6 and Ray 7 meet.

FIGS. 6 and 7 are still another embodiment of the present invention. In another embodiment of the present invention, a light diffusing shape or a specific material is partially inserted into a lens surface or a material constituting the lens.

FIG. 8 is a view showing that light incident on the lens is emitted by the specific material of FIGS.

FIG. 9 is another embodiment of FIG. 2, wherein a concave oblique surface is formed at the upper part of the lens to spread light at the center of the lens.

FIGS. 10 and 11 show embodiments in which the first refraction means and the second refraction means are constituted by a specific curvature in FIG. 2 or FIG. 9.

FIG. 12 shows another embodiment of the present invention.

The lens includes a first refracting means (surface) for refracting the light emitted from the light emitting element and advancing the light toward the inside of the lens, and a second refracting means (or surface) refracting the light propagating inside the lens toward the outside of the lens Wherein the lens of the second refraction means is provided with at least one tilt angle. Wherein at least one plane of the lens surface can serve as a support for placing another flat panel or image display element on the lens.

The lens first refracting means or the second refracting means is characterized in that at least one refraction angle is formed so that the emitted light of the light emitting element emits light evenly on the exit surface of the lens.

12 shows an example of a case where the first and second refraction means are each formed with two inclination angles.

The present invention includes a lens shape in which the lens inner side portion 603 in FIG. 12 has a saw tooth shape or a Fresnel lens shape as shown in FIGS. 13 and 14.

FIG. 15 shows a method of securing a further optical distance by providing the optical sheet 50 and the support plate 60 on the flat plate 40, thereby reducing the number of LEDs as a light source.

The present invention can reduce the cost and weight by eliminating the optical sheet, and the thickness of the optical sheet can be reduced by shortening the optical distance. In addition, high-quality images can be realized simultaneously with scanning and local dimming, which are advantages of direct backlighting.

It is to be understood that the foregoing description of the disclosure is for the purpose of illustration and that those skilled in the art will readily appreciate that other embodiments may be readily devised without departing from the spirit or essential characteristics of the disclosure will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

It is to be understood that the scope of the present invention is defined by the appended claims rather than the foregoing description and that all changes or modifications derived from the meaning and scope of the claims and equivalents thereof are included in the scope of the present invention .

Claims (10)

A light source (LED) emitting light; An optical system, comprising: means for setting a direction of travel of light radiated from a light source;
Characterized in that the outer or light exit surface of the means for changing the direction of the light (hereinafter referred to as a lens) comprises at least one plane or a planar equivalent shape An optical system characterized in that the outside or light exit surface of a means for changing the direction of light (hereinafter referred to as a lens) includes at least one plane or a plane equivalent configuration, Characterized by comprising an image-realizing display element for receiving an electrical signal to implement an image, Wherein an outer side or light exit surface of the means for changing the direction of light (hereinafter, referred to as a lens) includes at least one plane or a shape equivalent to a plane, wherein the plane of the lens Characterized in that a polarizing plate of the device is provided Wherein an outer side or light exit surface of the means for changing the direction of light (hereinafter referred to as a lens) includes at least one plane or a plane equivalent shape, wherein the optical element Wherein the optical system The optical element according to claim 2, wherein the optical element is a light diffuser sheet configured to have a predetermined thickness for dispersing light or a prism sheet having a predetermined thickness for changing the direction of light, And at least one or at least two of the polarization conversion elements for converting the polarized light into any one of polarized light. The lens of claim 1, 2, 3, or 4, which is provided in front of the traveling direction of the emitted light and changes the traveling direction of the light, includes a lens incidence side And a lens emergence side surface (second refracting surface) provided so that light passing through the lens is refracted or dispersed outside the lens. The optical system according to any one of claims 1, 2, 3, and 4, wherein the first refracting surface or the second refracting surface includes at least one curved surface or an oblique surface. In claim 7, wherein at least one part of the incidence side or exit side comprises a plurality of teeth or a Fresnel lens The optical sheet according to claim 6, wherein at least one support is provided between the optical sheet (50) and the space of the flat plate (40) to contact the optical sheet or the lower plate polarizer of the display element. The method of any one of claims 1, 2, 3, and 4, wherein the lens, which is provided in front of the traveling direction of the radiated light and changes the traveling direction of the light, refracts or disperses (diffuses) Wherein the optical system includes a material having a specific shape or a material having a refractive index different from that of the lens material.

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